Cellular acidosis triggers MondoA transcriptional activity by driving mitochondrial ATP production
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE117622 | GEO | 2019/01/23
REPOSITORIES: GEO
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Project description:Human MondoA requires glucose as well as other modulatory signals to function in transcription. One such signal is acidosis, which increases MondoA activity and also drives a protective gene signature breast cancer. How low pH controls MondoA transcriptional activity is unknown. We found that low pH medium increases mitochondrial ATP (mtATP), which is subsequently exported from the mitochondrial matrix. Mitochondria-bound hexokinase transfers a phosphate from mtATP to cytoplasmic glucose to generate glucose-6-phosphate (G6P), which is an established MondoA activator. The outer mitochondrial membrane localization of MondoA suggests that it is positioned to coordinate the adaptive transcriptional response to a cell’s most abundant energy sources, cytoplasmic glucose and mtATP. In response to acidosis, MondoA shows preferential binding to just two targets, TXNIP and its paralog ARRDC4. Because these transcriptional targets are suppressors of glucose uptake we propose that MondoA is critical for restoring metabolic homeostasis in response to high energy charge.
2019-01-23 | GSE125089 | GEO
Project description:BACKGROUND: Protein synthesis is regulated by the availability of amino acids, the engagement of growth factor signaling pathways and ATP levels sufficient to support translation. Crosstalk between these inputs is extensive, yet other regulatory mechanisms remain to be characterized. For example, the translation initiation inhibitor Rocaglamide A (RocA) induces Thioredoxin Interacting Protein (TXNIP). TXNIP is a negative regulator of glucose uptake, thus its induction by RocA links translation to the availability of glucose. MondoA is the principal regulator of glucose-induced transcription and its activity is triggered by the glycolytic intermediate, glucose 6-phosphate (G6P). MondoA responds to G6P generated by cytoplasmic glucose and mitochondrial ATP (mtATP), suggesting a critical role in the cellular response to these energy sources. TXNIP expression is entirely dependent on MondoA, therefore, we investigated how protein synthesis inhibitors impact its transcriptional activity. METHODS: We investigated how translation regulates MondoA activity using cell line models and loss-of-function approaches. We examined how protein synthesis inhibitors effect gene expression and metabolism using RNA-sequencing and metabolomics, respectively. The biological impact of RocA was evaluated using both cell line models and Patient-Derived Xenograft Organoid models. RESULTS: We discovered that multiple protein synthesis inhibitors, including RocA, increase TXNIP expression in a manner that depends on MondoA, a functional electron transport chain and mtATP synthesis. Furthermore, RocA increases mtATP and G6P levels and TXNIP induction depends on interactions between the Voltage-Dependent Anion Channel (VDAC) and hexokinase, which generates G6P. RocA treatment impacts the regulation of ~1200 genes and ~250 of those genes are MondoA-dependent. RocA treatment is cytotoxic to Triple Negative Breast Cancer cell lines and shows preferential cytotoxicity against ER- patient-derived breast cancer models. Finally, RocA-driven cytotoxicity is partially-dependent on MondoA or TXNIP. CONCLUSION: Our data suggest that protein synthesis inhibitors rewire metabolism, resulting in an increase in mtATP and G6P, the latter driving MondoA-dependent transcriptional activity. Further, MondoA is a critical component of the cellular transcriptional response to RocA. Our functional assays suggest that RocA or similar translation inhibitors may show efficacy against ER- tumors and that the levels of MondoA and TXNIP should be considered when exploring these potential treatment options.
2020-12-07 | GSE153499 | GEO
Project description:[1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for different length of time. We used microarrays to examine the genomic programs of cells incubated under lactic acidosis for different length of time [2] Metabolic profiling: MCF7 cells were exposed to control condition, 25mM lactic acidosis, glucose deprivation (zero glucose) and hypoxia (1% oxygen level). [3] Mouse study: Lactic acidosis triggers starvation response with paradoxical induction of TXNIP through MondoA. Wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs and the RNAs from cells were extracted with MiRVana kit (Ambion) and applied to Affymetrix 430A mouse chips We used microarrays to examine the genomic programs of cells incubated under different microenvironmental stresses. [1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for 1, 4, 12 and 24 hours. [2] Metabolic profiling: MCF7 cells were exposed to lactic acidosis, glucose deprivation and hypoxia for 4hours. [3] wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs.
2010-09-27 | E-GEOD-19123 | biostudies-arrayexpress
Project description:The MondoA transcription factor forms a heterocomplex with its obligate partner Mlx to regulate ~75% of glucose-dependent transcription. By mediating glucose-induced activation of thioredoxin-interacting protein (TXNIP), MondoA directly represses glucose uptake. Given the predominant role of MondoA in controlling glucose-dependent transcription and glucose uptake, we asked whether glutamine regulates MondoA activity. Expression profiles from glucose and glutamine starved BxPC-3 cells (-G-Q) were compared with those from cells grown in glucose only (+G-Q), glutamine only (-G+Q) or glucose plus glutamine (+G+Q). As expected, TXNIP expression was highly induced by glucose. However, the addition of glutamine repressed the glucose-dependent induction of TXNIP. We show that glutamine inhibits MondoA-dependent transcriptional activation of TXNIP by triggering the recruitment of a histone deacetylase-dependent corepressor to the amino terminus of MondoA. Consistent with the repression of TXNIP, glucose uptake is elevated in cells grown in the presence of glucose and glutamine. Finally, alpha-ketoglutarate, a tricarboxylic acid cycle intermediate, also blocks MondoA-dependent activation of TXNIP and stimulates glucose uptake. Together, these results suggest that glutamine-dependent mitochondrial anapleurosis stimulates glucose uptake by restricting TXNIP expression via MondoA:Mlx complexes. Four growth conditons; four biological replicates
2010-08-18 | E-GEOD-17632 | biostudies-arrayexpress
Project description:The MondoA transcription factor forms a heterocomplex with its obligate partner Mlx to regulate ~75% of glucose-dependent transcription. By mediating glucose-induced activation of thioredoxin-interacting protein (TXNIP), MondoA directly represses glucose uptake. Given the predominant role of MondoA in controlling glucose-dependent transcription and glucose uptake, we asked whether glutamine regulates MondoA activity. Expression profiles from glucose and glutamine starved BxPC-3 cells (-G-Q) were compared with those from cells grown in glucose only (+G-Q), glutamine only (-G+Q) or glucose plus glutamine (+G+Q). As expected, TXNIP expression was highly induced by glucose. However, the addition of glutamine repressed the glucose-dependent induction of TXNIP. We show that glutamine inhibits MondoA-dependent transcriptional activation of TXNIP by triggering the recruitment of a histone deacetylase-dependent corepressor to the amino terminus of MondoA. Consistent with the repression of TXNIP, glucose uptake is elevated in cells grown in the presence of glucose and glutamine. Finally, alpha-ketoglutarate, a tricarboxylic acid cycle intermediate, also blocks MondoA-dependent activation of TXNIP and stimulates glucose uptake. Together, these results suggest that glutamine-dependent mitochondrial anapleurosis stimulates glucose uptake by restricting TXNIP expression via MondoA:Mlx complexes.
2009-08-17 | GSE17632 | GEO
Project description:[1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for different length of time. We used microarrays to examine the genomic programs of cells incubated under lactic acidosis for different length of time [2] Metabolic profiling: MCF7 cells were exposed to control condition, 25mM lactic acidosis, glucose deprivation (zero glucose) and hypoxia (1% oxygen level). [3] Mouse study: Lactic acidosis triggers starvation response with paradoxical induction of TXNIP through MondoA. Wild-type mouse embryo fibroblasts (MEFs) and TXNIP-null MEFs were exposed to Ctrl versus lactic acidosis conditions for 24hrs and the RNAs from cells were extracted with MiRVana kit (Ambion) and applied to Affymetrix 430A mouse chips We used microarrays to examine the genomic programs of cells incubated under different microenvironmental stresses.
2010-09-27 | GSE19123 | GEO
Project description:Objective Cancer cells convert more glucose into lactate than healthy cells, what results in their growth advantage. Pyruvate kinase (PK) is a key rate limiting enzyme in this process, what makes it a promising potential therapeutic target. However, currently it is still unclear what consequences the inhibition of PK has on cellular processes. Here, we systematically investigate the consequences of PK depletion for gene expression, histone modifications and metabolism. Methods Epigenetic, transcriptional and metabolic targets were analysed in different cellular and animal models with stable knockdown or knockout of PK. Results Depleting PK activity reduces the glycolytic flux and causes accumulation of glucose-6-phosphate (G6P). Such metabolic perturbation results in stimulation of the activity of a heterodimeric pair of transcription factors MondoA and MLX but not in a major reprogramming of the global H3K9ac and H3K4me3 histone modification landscape. The MondoA:MLX heterodimer upregulates expression of thioredoxin-interacting protein (TXNIP) – a tumour suppressor with multifaceted anticancer activity. This effect of TXNIP upregulation extends beyond immortalised cancer cell lines and is applicable to multiple cellular and animal models. Conclusions Our work shows that actions of often pro-tumorigenic PK and anti-tumorigenic TXNIP are tightly linked via a glycolytic intermediate. We suggest that PK depletion stimulates the activity of MondoA:MLX transcription factor heterodimers and subsequently, increases cellular TXNIP levels. TXNIP-mediated inhibition of thioredoxin (TXN) can reduce the ability of cells to scavenge reactive oxygen species (ROS) leading to the oxidative damage of cellular structures including DNA. These findings highlight an important regulatory axis affecting tumour suppression mechanisms and provide an attractive opportunity for combination cancer therapies targeting glycolytic activity and ROS-generating pathways
2023-07-06 | GSE235388 | GEO
Project description:Objective Cancer cells convert more glucose into lactate than healthy cells, what results in their growth advantage. Pyruvate kinase (PK) is a key rate limiting enzyme in this process, what makes it a promising potential therapeutic target. However, currently it is still unclear what consequences the inhibition of PK has on cellular processes. Here, we systematically investigate the consequences of PK depletion for gene expression, histone modifications and metabolism. Methods Epigenetic, transcriptional and metabolic targets were analysed in different cellular and animal models with stable knockdown or knockout of PK. Results Depleting PK activity reduces the glycolytic flux and causes accumulation of glucose-6-phosphate (G6P). Such metabolic perturbation results in stimulation of the activity of a heterodimeric pair of transcription factors MondoA and MLX but not in a major reprogramming of the global H3K9ac and H3K4me3 histone modification landscape. The MondoA:MLX heterodimer upregulates expression of thioredoxin-interacting protein (TXNIP) – a tumour suppressor with multifaceted anticancer activity. This effect of TXNIP upregulation extends beyond immortalised cancer cell lines and is applicable to multiple cellular and animal models. Conclusions Our work shows that actions of often pro-tumorigenic PK and anti-tumorigenic TXNIP are tightly linked via a glycolytic intermediate. We suggest that PK depletion stimulates the activity of MondoA:MLX transcription factor heterodimers and subsequently, increases cellular TXNIP levels. TXNIP-mediated inhibition of thioredoxin (TXN) can reduce the ability of cells to scavenge reactive oxygen species (ROS) leading to the oxidative damage of cellular structures including DNA. These findings highlight an important regulatory axis affecting tumour suppression mechanisms and provide an attractive opportunity for combination cancer therapies targeting glycolytic activity and ROS-generating pathways
2023-07-06 | GSE235387 | GEO
Project description:Although a large set of data is available concerning organogenesis in animal models, information remains scarce on human organogenesis. In this work, we performed temporal mapping of human fetal pancreatic organogenesis using cell surface markers. We demonstrate that in the human fetal pancreas at 7 weeks of development, the glycoprotein 2 (GP2) marks a multipotent cell population that will differentiate either into the acinar, ductal and endocrine lineages. Development towards the acinar lineage is paralleled by a substantial increase in GP2 expression. Conversely, a subset of the multipotent GP2+ population undergoes endocrine differentiation by down-regulating GP2 and CD142 and turning on NEUROG3, an early marker of endocrine differentiation. Endocrine maturation will progress by up-regulating SUSD2 and lowering ECAD levels. Finally, we show that in vitro differentiation of pancreatic endocrine cells derived from human pluripotent stem cells mimics key in vivo events. Our work constitutes a powerful approach to more precisely define intermediate cell population during conversion of multipotent progenitors into the 3 main human pancreatic cell types (acinar, ductal and endocrine) in vivo. As such, the data pave the way to extend our understanding of the origin of mature human pancreatic cell types and how such lineage decisions are regulated. While the mechanisms by which glucose regulates insulin secretion from pancreatic beta cells are now well described, the way glucose modulates gene expression in such cells needs more understanding. Here, we demonstrate that MondoA, but not its paralogue ChREBP, is the predominant glucose-responsive transcription factor in human pancreatic beta EndoC-βH1 cells and in human islets. In high glucose conditions, MondoA shuttles to the nucleus where it is required for the induction of the glucose-responsive genes ARRDC4 and TXNIP, the latter being a protein strongly linked to beta-cell dysfunction and diabetes. Importantly, increasing cAMP signaling in human beta cells, using forskolin or the GLP-1 mimetic Exendin-4, inhibits the shuttling of MondoA and potently inhibits TXNIP and ARRDC4 expression. Furthermore, we demonstrate that modulating MondoA expression functionally affects glucose uptake. These results highlight MondoA as a novel target in beta cells that coordinates transcriptional response to elevated glucose levels.
2017-05-04 | GSE98501 | GEO
Project description:MondoA (also known as MLXIP), a member of the MYC interactome, has been described as an example of a metabolic sensor. By assessing patient data sets we found that MondoA overexpression is associated with a worse survival in pediatric common acute lymphoblastic leukemia (B-ALL). Using CRISPR/Cas9 and RNA interference approaches, we observed that MondoA depletion reduces transformational capacity of B-ALL cells in vitro and dramatically inhibits malignant potential in an in vivo mouse model. Interestingly, reduced expression of MondoA in patient data sets correlated with enrichment in metabolic pathways. The loss of MondoA correlated with increased tricarboxylic acid (TCA) cycle activity. Mechanistically, MondoA senses metabolic stress in B-ALL cells by restricting oxidative phosphorylation through reduced PDH activity. Glutamine starvation conditions greatly enhance this effect and highlight the inability to mitigate metabolic stress upon loss of MondoA in B-ALL. CHIPseq revealed a modest but highly significant redistribution of MYC towards binding sites shared with MondoA upon loss of MondoA.
2021-04-04 | GSE168865 | GEO